ExprRootNode<?> expr = (new ExpressionParser("-11")).parseExpression();
NegativeOpNode negOp = (NegativeOpNode) expr.getChild(0);
assertEquals(11, ((IntegerNode) negOp.getChild(0)).getValue());
expr = (new ExpressionParser("not false")).parseExpression();
NotOpNode notOp = (NotOpNode) expr.getChild(0);
assertEquals(false, ((BooleanNode) notOp.getChild(0)).getValue());
expr = (new ExpressionParser("90 -14.75")).parseExpression();
MinusOpNode minusOp = (MinusOpNode) expr.getChild(0);
assertEquals(90, ((IntegerNode) minusOp.getChild(0)).getValue());
assertEquals(14.75, ((FloatNode) minusOp.getChild(1)).getValue());